(1) Field of Invention
The present invention relates to a laminate comprising a thermoplastic elastomer layer and a polyamide, polyurethane or polyester layer and a molded article formed therefrom. More specifically, the present invention relates to a laminate comprising a layer composed of a partially crosslinked graft-modified polyolefin elastomer obtained by dynamically heat-treating a mixture of a peroxide-crosslinked olefin copolymer rubber and an olefinic plastic with an unsaturated carboxylic acid or derivative thereof, an unsaturated epoxy monomer or an unsaturated hydroxy monomer in the presence of an organic peroxide and a layer composed of a polyamide, polyurethane or polyester, which is valuable as automobile interior parts or sealing materials, and also to a glass run channel molded from this laminate.
(2) Description of the Prior Art
A polyvinyl chloride sheet having an embossed surface and a leather pattern boarded thereon has been used for automobile interior parts such as a floor, a wall or a ceiling panel.
However, since a plasticizer is incorporated in polyvinyl chloride, this polyvinyl chloride sheet is defective in that the surface of the sheet is made sticky by the plasticizer or the sheet becomes hard or the interior of an automobile becomes foggy because of evaporation of the plasticizer.
Instead of this single sheet of polyvinyl chloride, there has been used a laminate comprising a polyvinyl chloride sheet backed with a foamed layer and, if necessary, a resin aggregate layer. This laminate is prepared through the following steps.
(1) Soft polyvinyl chloride is calendered to form a sheet.
(2) The surface of the sheet is coated with a mixture of a polyol and a polyisocyanate and delustering is effected by a urethane treatment.
This delustering treatment is performed so as to prevent the sheet surface from becoming glossy at the heat molding step (7) described below.
(3) The sheet surface is embossed to form a boarded leather pattern on the sheet surface.
(4) The back surface of the sheet having the embossed surface is subjected to a flame treatment to melt the back surface portion, and a foamed polyurethane sheet supplied separately is press-bonded to the molten back surface by means of a roll.
(5) An adhesive layer is further formed on the foamed polyurethane sheet side of the resulting laminate comprising the polyvinyl chloride sheet and the foamed polyurethane sheet.
(6) A resin aggregate having a predetermined shape is formed by heat molding such as vacuum forming or compressed air forming.
(7) The polyvinyl chloride/foamed polyurethane/adhesive laminate is preliminarily heated, and the laminated is placed on the shaped resin aggregate and the assembly is integrated by heat molding.
The conventional laminate to be used as an interior part is defective in that the preparation process is complicated as described above.
However, troubles such as the sticky surface and the fogging of the interior of an automobile similarly arise in case of this laminate, because a polyvinyl chloride sheet containing a plasticizer is used.
A glass run channel, which is one important sealing material for an automobile, has in the cross-section thereof a groove-like body portion and a tongue-like strainer portion expanded from the vicinity of the top of the side wall of the groove-like body portion toward the center.
In the conventional glass run channel, in order to attain good parting of the strainer portion from the glass contact part and prevent contamination of glass, a nylon film or the like is applied to the surface of glass contact part by bonding, and in order to decrease the area of contact with glass, an embossing treatment is conducted before or after lamination of the nylon film or the like.
As other materials, there can be mentioned (1) a composite material comprising a cured rubber composed mainly of an ethylene/propylene/diene copolymer rubber excellent in weatherability and heat resistance, an adhesive and a nylon fiber, (2) a composite material comprising the above-mentioned cured rubber and an adhesive excellent in abrasion resistance, and (3) soft polyvinyl chloride for profile extrusion molding. The materials (1) and (2) are excellent in weatherability, heat resistance and dimensional stability because they comprise as the base material a cured ethylene/propylene/diene copolymer rubber excellent in weatherability, and heat resistance. However, the preparation process comprises the step of kneading the ethylene/propylene/diene copolymer rubber with a filler, the extrusion molding step, the surface buffing step, the adhesive coating step, the drying step, and the fiber implanting step and the preparation process is very complicated. On the other hand, since the material (3) is formed by profile extrusion molding of soft polyvinyl chloride, the preparation process is simplified, but the material (3) is insufficient in heat resistance or dimensional stability and is inferior to the materials (1) and (2) in practical performances.